As outlined by the 2006 brochure from the RIA users community, one of the more succinct descriptions of opportunities associated with a new facility, "[t]he fields of nuclear structure and astrophysics provide the link between our understanding of the fundamental constituents of nature and the understanding of the matter of which we, the Earth, and stars are made. Expertise in these areas is also central to applied fields such as energy, security, and medicine."

The study of nuclei is a core component of modern science, helping to connect the very small (quantum mechanics) with the unimaginably vast (stars, galaxies and the cosmos). Thanks to a host of productive collaborations between theorists and experimentalists, the last few years have accelerated our understanding the nucleus.

However, there remains much mystery, too.

Consider that it's been more than a half century since the discovery of the proton and neutron, the building-block particles that comprise nuclei. However, researchers still can't predict exactly how these particles interact with each other to form all the matter that we see around us.

Throughout science, researchers advance their understanding of core principles by studying extremes in nature. In nuclear science, this means probing nuclei that generally exist only in environments such as hyper-dense neutron stars or cataclysmic supernova.

FRIB will make it possible to produce more of these nuclei, in the process addressing a host of open questions about the physics of nuclei. These questions include:

Nuclear physics and astronomy are inextricably intertwined. In fact, more than ever, astronomical discoveries are driving the frontiers of nuclear physics while our knowledge of nuclei is driving progress in understanding the universe.

Because of its powerful technical capabilities, FRIB will forge tighter links between the two disciplines. Rare isotopes play a critical role in the evolution of stars and other cosmic phenomena such as novae and supernovae, but up to now the most interesting rare isotopes have been largely out of the reach of terrestrial experiments. FRIB will provide access to most of the rare isotopes important in these astrophysical processes, thus allowing scientists to address questions such as:

How are the elements from iron to uranium created?

How do stars explode?

What is the nature of neutron star matter?

Recent astronomical missions such as the Hubble Space Telescope, Chandra X-ray Observatory, Spitzer Space Telescope, and the Sloan Digital Sky Survey have provided new and detailed information on element synthesis, stellar explosions, and neutron stars over a wide range of wavelengths. However, scientists attempting to interpret these observations have been constrained by the lack of information on the physics of unstable nuclei.

FRIB and future astronomy missions such as the Joint Dark Energy Mission, and the Advanced Compton Telescope will complement each other and provide a potent combination of tools to discover answers to important questions that confront the field.

Nuclear and particle physicists study fundamental interactions for two basic reasons: to clarify the nature of the most elementary pieces of matter and determine how they fit together and interact. Most of what has been learned so far is embodied in the Standard Model of particle physics, a framework that has been both repeatedly validated by experimental results and is widely viewed as incomplete.

"[Scientists] have been stuck in that model, like birds in a gilded cage, ever since [the 1970s]," wrote Dennis Overbye in a July 2006 essay for The New York Times. "The Standard Model agrees with every experiment that has been performed since. But it doesn't say anything about the most familiar force of all, gravity. Nor does it explain why the universe is matter instead of antimatter, or why we believe there are such things as space and time."

Rare isotopes produced at FRIB's will provide excellent opportunities for scientists to devise experiments that look beyond the Standard Model and search for subtle indications of hidden interactions and minutely broken symmetries and thereby help refine the Standard Model and search for new physics beyond it.

FRIB will provide research quantities of rare isotopes that can be used to develop new medical diagnostics and treatment of disease. It will also play an important role in understanding small-scale objects by providing isotopes for implantation and hence probing subtle effects on the atomic scale. Finally, understanding how nuclei interact is essential to national security and design of a new generation of safer nuclear reactors.

A recent report by the National Academies of Science found that "[a]pplications in [stockpile stewardship, materials science, medical research and nuclear reactors] have long relied on a wide variety of radioisotopes. At the present time, each of these areas would be significantly advanced by a facility with high isotope production rates."

Often, work in these areas can proceed "parasitically" to the FRIB primary nuclear science operations, thereby optimizing the overall scientific output. Research in several of these areas is already being actively pursued at other facilities such as ISOLDE at CERN in Geneva, Switzerland and ISAC at TRIUMF in Vancouver, Canada.

Source: 2006 brochure from the RIA users community, 2007 report "Scientific Opportunities with a Rare-Isotope Facility in the United States" from the National Academies of Science